Stephen P. Fulton

Prospective Study of the Emfit Movement Monitor

Sudden unexplained death in epilepsy (SUDEP) is associated with generalized tonic-clonic seizures and occurs most often when patients are in bed. There are several seizure detection monitors on the market, but little data are available on the sensitivity and specificity of these devices. We recently tested 2 models of seizure detection alarms with disappointing results. Here we tested the Emfit movement monitor on children with various seizure types who also had standard video electroencephalography (EEG), cardiopulmonary, and nursing monitoring. Video EEG records were reviewed to detect any seizures. In 45 patients, 78 seizures were recorded by video EEG. The Emfit movement monitor captured 23 seizure events (30%) in total, and 15 of the 28 (54%) that occurred during sleep. Most importantly, the alarm was activated with 11 of the 13 (85%) generalized tonic-clonic seizures that occurred in sleeping children. The Emfit movement monitor performed very well in comparison to previously tested devices.

Language mapping using high gamma electrocorticography, fMRI, and TMS versus electrocortical stimulation

OBJECTIVE The aim of the present study was to compare localization of the language cortex using cortical stimulation mapping (CSM), high gamma electrocorticography (hgECoG), functional magnetic resonance imaging (fMRI), and transcranial magnetic stimulation (TMS). METHODS Language mapping using CSM, hgECoG, fMRI, and TMS were compared in nine patients with epilepsy. Considering CSM as reference, we compared language mapping approaches based on hgECoG, fMRI, and TMS using their sensitivity, specificity, and the results of receiver operating characteristic (ROC) analyses. RESULTS Our results show that areas involved in language processing can be identified by hgECoG, fMRI, and TMS. The average sensitivity/specificity of hgECoG, fMRI, and TMS across all patients was 100%/85%, 50%/80%, and 67%/66%, respectively. The average area under the ROC curve of hgECoG, fMRI, and TMS across CSM-positive patients was 0.98, 0.76, and 0.68, respectively. CONCLUSIONS There is considerable concordance between CSM, hgECoG, fMRI, and TMS language mapping. Our results reveal that hgECoG, fMRI, and TMS are valuable tools for presurgical language mapping. SIGNIFICANCE Language mapping on the basis of hgECoG, fMRI, and TMS can provide important additional information, therefore, these methods can be used in conjunction with CSM or as an alternative, when the latter is deemed impractical.

Prospective study of 2 bed alarms for detection of nocturnal seizures

For parents of children with epilepsy, seizures occurring in sleep are a major concern. Risk factors for sudden unexplained death in epilepsy patients include being in bed and generalized tonic-clonic seizures. A device for detecting nocturnal seizure activity would be valuable. Children with various seizure types undergoing evaluation had standard video electroencephalography (EEG), cardiopulmonary and nursing monitoring, and 1 of 2 models (ST-2 and MP5) of a Medpage bed alarm. The video EEG record was reviewed to detect any seizures missed by the bed alarms or caregivers. The ability of the bed alarms to detect motor seizures in general and specific seizure types was tested. In 15 patients, 69 seizures were recorded by video EEG. The ST-2 did not detect any nocturnal seizures. The MP5 alarm detected 1 of 15 in sleeping patients: a generalized tonic-clonic seizure. The Medpage seizure alarms do not appear to adequately detect nocturnal seizures.

SmartWatch by SmartMonitor: Assessment of Seizure Detection Efficacy for Various Seizure Types in Children, a Large Prospective Single-Center Study

INTRODUCTION Patients with epilepsy and their caregivers are constantly burdened with the possibility of a seizure and its consequences, such as accidents, injuries, and sudden unexplained death in epilepsy. It is the unpredictable nature of seizures that often affects both patients with seizures and their caregivers, limits independence, and hinders quality of life. There are several types of motion detectors on the market, each with varying degrees of sensitivity. MATERIAL AND METHODS We prospectively tested the SmartWatch, a wrist-worn monitor, on children, adolescents, and young adults with various types of seizures in an epilepsy monitoring unit. Confirmation of seizure type and if there was rhythmic upper extremity jerking associated with the seizure was determined by review of the video electroencephalograph. This was compared with the standard detection system of the watch. RESULTS This study analyzed a total of 191 seizures in 41 patients aged 5-41 years. Fifty-one of the seizures were generalized tonic-clonic. Forty-seven of the seizures had a rhythmic arm movement component. The SmartWatch detected 30 seizures (16%) of the total, 16 (31%) of the generalized tonic-clonic seizures, and 16 (34%) seizures associated with rhythmic arm movements. DISCUSSION Overall, only a minority of generalized tonic-clonic seizures or seizures with rhythmic movements were detected, highlighting the need for an effective seizure detection device.

Angiocentric Glioma―Induced Seizures in a 2-Year-Old Child

A 2-year-old child presented with medically refractory seizures and was found to have a right frontoparietal parasagittal angiocentric glioma. Depth electrodes were used to document ictal onset from within the tumor rather than from the surrounding tissues. Ictal activity then spread to a wide area on the cortical surface, including the region around the tumor and hand motor cortex. Lesionectomy permitted sparing of adjacent areas of eloquent cortex, and the child is now seizure-free on monotherapy.

Passive language mapping with magnetoencephalography in pediatric patients with epilepsy

OBJECT Functional mapping is important for determining surgical candidacy and also in epilepsy surgery planning. However, in young children and uncooperative patients, language mapping has been particularly challenging despite the advances in performing noninvasive functional studies. In this study the authors review a series of children with epilepsy who underwent language mapping with magnetoencephalography (MEG) while sedated or sleeping, to determine receptive language localization for presurgical evaluation. METHODS The authors undertook a retrospective review of patients who underwent MEG between December 2007 and July 2009, and identified 15 individuals who underwent passive language testing as part of their presurgical evaluation because they were unable to participate in traditional language testing, such as Wada or functional MRI. Factors necessitating passive language testing included age and neurocognitive development. RESULTS Three of the 15 patients were deemed candidates for epilepsy surgery based on the results from standard preoperative testing, including video electroencephalography, MRI, and passive receptive language testing using MEG technology. The MEG studies were used successfully to localize language in all 3 patients, creating opportunities for seizure freedom through surgery that would not otherwise have been available. All 3 patients then underwent resective epilepsy surgery without experiencing postoperative language deficits. CONCLUSIONS This case series is the first to look at language mapping during sleep (passive language mapping) in which MEG was used and is the first to evaluate passive language testing in a patient population with intracranial pathological entities. This case series demonstrates that MEG can provide an alternative method for receptive language localization in patients with barriers to more traditional language testing, and in these 3 cases surgery was performed safely based on the results.

Assessing Motor Function in Young Children With Transcranial Magnetic Stimulation

OBJECTIVE Accurate noninvasive assessment of motor function using functional MRI (fMRI) and magnetoencephalography (MEG) is a challenge in patients who are very young or who are developmentally delayed. In such cases, passive mapping of the sensorimotor cortex is performed under sedation. We examined the feasibility of using transcranial magnetic stimulation (TMS) as a motor mapping tool in awake children younger than 3 years of age. METHODS Six children underwent motor mapping with TMS while awake as well as passive sensorimotor mapping under conscious sedation with MEG during tactile stimulation (n = 5) and fMRI during passive hand movements (n = 4). RESULTS Stimulation of the motor cortex via TMS successfully elicited evoked responses in contralateral hand muscles in 5 patients. The location of primary motor cortex in the precentral gyrus identified by TMS corresponded with the postcentral location of the primary sensory cortex identified by MEG in 2 patients and to the sensorimotor cortex identified by fMRI in 3 children. In this cohort, we demonstrate that TMS can illuminate abnormalities in motor physiology including motor reorganization. We also demonstrate the feasibility of using TMS-derived contralateral silent periods to approximate the location of motor cortex in the absence of an evoked response. When compared to chronological age, performance functioning level appears to be better in predicting successful mapping outcome with TMS. CONCLUSIONS Our findings indicate that awake TMS is a safe alternative to MEG and fMRI performed under sedation to localize the motor cortex and provides additional insight into the underlying pathophysiology and motor plasticity in toddlers.

Variation in the topography of the speech production cortex verified by cortical stimulation and high gamma activity

In this study, we have addressed the question of functional brain reorganization for language in the presence and absence of anatomical lesions in two patients with epilepsy using cortical stimulation mapping and high gamma (HG) activity in subdural grid recordings. In both, the expressive language cortex was defined as the cortical patch below the electrode(s) that when stimulated resulted in speech arrest, and during speech expression tasks generated HG activity. This patch fell within the borders of Broca’s area, as defined anatomically, in the case of the patient with a lesion, but outside that area in the other, lesion-free patient. Such results highlight the necessity for presurgical language mapping in all cases of surgery involving the language-dominant hemisphere and suggest that HG activity during expressive language tasks can be informative and helpful in conjunction with cortical stimulation mapping for expressive language mapping.

Vagus Nerve Stimulation in Intractable Epilepsy Associated With SCN1A Gene Abnormalities

Mutations in the SCN1A gene cause a spectrum of epilepsy syndromes. There are 2 syndromes that are on the severe end of this spectrum. The classic severe form, Dravet syndrome, is an epileptic encephalopathy of childhood, causing cognitive decline as well as intractable seizures. Severe Myoclonic Epilepsy of Infancy–Borderline (SMEIB) is a term used to include cases with similar severities as those with Dravet syndrome, but lacking a single feature of classic severe myoclonic epilepsy of infancy. Vagus nerve stimulation is a nonpharmacologic treatment for intractable epilepsy. A retrospective review was conducted of patients with deleterious SCN1A mutations who had vagus nerve stimulation placement for treatment of their intractable epilepsy. These children had onset of their epilepsy between 3 and 29 months of age. Seizure control was assessed 6 months after implantation. Twenty patients are included in the study, with 12 implanted at our institution. Nine of the 12 patients implanted at our institution, who had confirmed pre- and post-implantation seizure assessments, showed improvement in seizure control, which was defined as >50% reduction in generalized tonic-clonic seizures, and 4 of those 12 reported improvement in cognitive or speech development. Seven of the 8 patients not implanted at our institution reported subjective benefit, with 4 relating “marked improvement” or seizure freedom. Vagus nerve stimulation appears to impart a benefit to children with deleterious SCN1A gene abnormalities associated with intractable epilepsy.

Predicting postoperative language outcome using presurgical fMRI, MEG, TMS, and high gamma ECoG

OBJECTIVE To predict the postoperative language outcome using the support vector regression (SVR) and results of multimodal presurgical language mapping. METHODS Eleven patients with epilepsy received presurgical language mapping using functional MRI (fMRI), magnetoencephalography (MEG), transcranial magnetic stimulation (TMS), and high-gamma electrocorticography (hgECoG), as well as pre- and postoperative neuropsychological evaluation of language. We constructed 15 (24-1) SVR models by considering the extent of resected language areas identified by all subsets of four modalities as input feature vector and the postoperative language outcome as output. We trained and cross-validated SVR models, and compared the cross-validation (CV) errors of all models for prediction of language outcome. RESULTS Seven patients had some level of postoperative language decline and two of them had significant postoperative decline in naming. Some parts of language areas identified by four modalities were resected in these patients. We found that an SVR model consisting of fMRI, MEG, and hgECoG provided minimum CV error, although an SVR model consisting of fMRI and MEG was the optimal model that facilitated the best trade-off between model complexity and prediction accuracy. CONCLUSIONS A multimodal SVR can be used to predict the language outcome. SIGNIFICANCE The developed multimodal SVR models in this study can be utilized to calculate the language outcomes of different resection plans prior to surgery and select the optimal surgical plan.